https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/Lens-ring-keeps-going-back-and-forth-keeps-focusing-in-and-out/m-p/35155#M74416 <P>You can try to clean the lens contact. Have you dropped your lens or something? You may need to send it in for service (Sigma has 5 years warranty).</P> Wed, 24 Jul 2013 23:07:16 GMT hsbn 2013-07-24T23:07:16Z https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/Lens-ring-keeps-going-back-and-forth-keeps-focusing-in-and-out/m-p/35151#M74415 <P><SPAN>Recently I have been having issues with the auto-focus on my camera. &nbsp;The focus ring just keeps turning back and forth and takes forever to focus, if it ever does. &nbsp;It gets even worse when it's dark. &nbsp;Any answers to what might be causing this? maybe sensor issues? &nbsp;The lens seems clear and I cleaned the filter. &nbsp;I a using a Rebel T2i and a Sigma EX OS17-50mm f/2.8. &nbsp;Any suggestions would be helpful, thanks!</SPAN></P> Wed, 24 Jul 2013 22:51:15 GMT https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/Lens-ring-keeps-going-back-and-forth-keeps-focusing-in-and-out/m-p/35151#M74415 TreyfromECU 2013-07-24T22:51:15Z https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/Lens-ring-keeps-going-back-and-forth-keeps-focusing-in-and-out/m-p/35155#M74416 <P>You can try to clean the lens contact. Have you dropped your lens or something? You may need to send it in for service (Sigma has 5 years warranty).</P> Wed, 24 Jul 2013 23:07:16 GMT https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/Lens-ring-keeps-going-back-and-forth-keeps-focusing-in-and-out/m-p/35155#M74416 hsbn 2013-07-24T23:07:16Z